Research On Accuracy Stability Of Feed System Of The Six-axis PCB CNC Drilling Machine

With the rapid development and application of precision manufacturing precision machining technology,and accuracy is an important index to measure the performance of CNC machine tools has been of concern to people,but in the practical application,the long-term test of high precision machine tools but also withstand various complicated situations,and can maintain its accuracy and stability,which is proposed to maintain the accuracy.At present,most of the researches focus on how to improve the precision of NC machine tools,therefore,improve the accuracy of retention plays a key role in the development of China’s high precision CNC machine tool.The research and application of high speed NC drilling machine of PCB six axis linear motor based on Sichuan science and technology support project",and the PCB six axis CNC drilling machine feed system as the research object.According to the field operation data,the precision maintenance of feed system is studied by using the method of precision retention analysis based on fault formation process.In order to improve the accuracy of the maintenance,combined with the application of linear motor in high precision CNC machine tools,the PCB six axis CNC drilling machine feed system was redesigned.Specific contents include the following:(1)Starting from the working principle and structure of the feed system,analyzing the characteristics of the feed system and the error type and error influence.According to the characteristics of the feed system working principle and structure,dividing subsystems,and using failure mode and its method of effects analysis(FMEA)for the failure analysis of feed system,the reason of fault location,fault mode,fault feed system detailed statistical analysis,maintain analysis and redesign of feed system and provide the basis for the accuracy.(2)Based on the fault analysis,using the method of precision retention analysis based on fault formation process,the Weibull distribution model and linear regression method are used to calculate the reliability statistics of the actual accuracy data,the completion of the feed system to maintain the accuracy of analysis.Results the accuracy of the fault feed system obeys the two parameter Weibull distribution shape parameter,scale parameter =13 of=943.88,and calculate the accuracy of retention time is obtained.(3)The fault analysis of the conclusions,to apply load lightweight,linear motor as the design idea,in order to improve the accuracy of retention for the purpose of redesign of the fourth generation feed system of the six axis linear motor PCB CNC drilling machine,through the load calculation and analysis,the linear motor and the guide rail system of the feed system are selected and checked,and finite element analysis of the key transmission parts.(4)Designed to maintain the accuracy of detection experiment,the use of professional testing equipment were positioning accuracy of six axis linear motor feed system of the third generation of PCB six axis NC drilling machine and the fourth generation of PCB were detected by comparative analysis of the test results,verify the fourth generation drilling machine feeding system in precision to maintain the advantage.The experimental results show that the precision of the fourth generation drilling machine feeding system has been improved,and its accuracy has been improved.